Determining distance between two coordinates

[Todd300Participant]

How do I determine the distance between two sets of coordinates by using math, not a GPS? Doing this will help me on the way to solve a puzzle. Thanks 🙂

[hogrodMember]

You can use the program FizzyCalc (free) to do this for you. once you have the program I believe what you are looking for is under the distance tab.

http://www.fizzymagic.net/Geocaching/FizzyCalc/

[Team DeejayParticipant]

If you are working on the puzzle that I think you are working on, pay close attention to the description and hints. Some people’s view of the world is skewed, similar to that of people in the 12th century. I wonder if they were worried about sailing off the edge of the world!

[Team Black-CatParticipant]

Unless you REALLY need to do the math, you should probably find an online utility to get the distance.

But since you asked…
I recently created a function for a program I’m working on. Here’s what I did.
Keep in mind that I am a programmer and not a mathmatician…

Start with decimal degrees instead of degrees and minutes. You can do the conversion on GC.com.

Convert each coordinate to radians:

A=(Point1Latitude * Pi /180)

B=(Point1Longitude * Pi /180)

C=(Point2Latitude * Pi /180)

D=(Point2Latitude * Pi /180)

Get the difference between the angles:

DLat=C-A

DLon=D-B

Now it gets fun…

X = Sin(DLat / 2) * Sin(DLat / 2) + Cos(A) * Cos(C) * Sin(DLon / 2) * Sin(DLon / 2)

Y = 2 * Atan2(Sqrt(X), Sqrt(1 - X))

To get miles, multiply Y by 3959.

Did I get it right Mathman?

Edited to add:
Atan2 might not be on your calculator. It is the angle whose tanget is the quotent of the two specified numbers.

[CodeJunkieParticipant]

@Team Black-Cat wrote:

A=(Point1Latitude * Pi /180)

B=(Point1Longitude * Pi /180)

C=(Point2Latitude * Pi /180)

D=(Point2Latitude * Pi /180)

I assume you meant Point2Longitude for D.

[Team Black-CatParticipant]

Yes I did, and thanks for catching that. I can’t edit the original post anymore…

[Team Black-CatParticipant]

The hard way
The easy way

[MiataParticipant]

@Team Black-Cat wrote:

The hard way
The easy way

Much better……

[CodeJunkieParticipant]

For a whole bunch of different versions of this, do a “Google” search using the following words:
gps distance calculator

[Team Black-CatParticipant]

@codejunkie wrote:

For a whole bunch of different versions of this, do a “Google” search using the following words:
gps distance calculator

If you’re having trouble sleeping, search for “haversine”.

[Author]

Posts